Home secretary Theresa May ordered a consultation into stop and search powers (Picture: PA)

Police stop and search powers haven’t stopped Barry from breaking the law – he has no criminal convictions.

But they have deterred the 20-year-old who lives on an estate in Kilburn, north London, from spending time in his neighbourhood or even going on shopping trips with his mother.

Despite being stopped more times than he can remember (approximate estimate: more than 100), police have never found anything on him.

When he used to hang around the area, he says he could find himself being stopped twice a day – ‘not including strip searches’.

And he claims that if he tried to record the encounter, his phone could be taken for up to three weeks and returned with the footage deleted.

‘I don’t even want to shop with my mum any more,’ he said. ‘It just looks bad. You’ll just be going to the shops – you’ll be stopped and then taken for a strip search. I feel embarrassed.

‘Often, the local police station is full so they would drive me to Wembley and refuse to bring me back. After about three hours, I’d be released, but have no money on me and be stranded.’

Barry isn’t his real name; he feared he would be targeted yet further by police if they knew he had spoken out.

‘When I have complained, I’ve been told, “shut the f*** up or we’re going to do your door in”. That is their favourite line.’

In January, Stuart Lawrence, brother of murdered teenager Stephen, lodged a formal complaint with the Metropolitan Police, alleging that he had been stopped or searched by officers 25 times since he was 17. But it is not just men.

Janet Hills, chairwoman of the Metropolitan Black Police Association, told Metro: ‘I’ve been stopped and searched when I’ve been on the street more times than I’ve used the actual power.’

And a solicitor who works with youngsters at the sharp end of stop and search says she frequently feels intimidated by police.

Once, she asked for an officer’s badge number to make a complaint on behalf of a client – before he covered it up with his seatbelt and said: ‘I dare you’.

She said: ‘If I had moved it, he would have arrested me for assault, most probably.’

Nor is it only the black community raising the alarm.

Research by the London School of Economics into the 2011 riots identified the operation of the stop and search laws as a key factor behind the unrest.

Earlier this month, the police watchdog said one in four people stopped by officers is searched unlawfully – a week before an inquiry by the Independent Police Complaints Commission found the Metropolitan Police is failing to fairly tackle complaints of racism by its officers.

To pre-empt these findings, home secretary Theresa May announced a consultation into stop and search, which runs until August 13.

She lamented the fact that if you are black, you are still seven times more likely to be targeted, telling parliament: ‘At its best, stop and search is a vital power in the fight against crime. At its worst, it’s a waste of police time and serves to undermine public confidence in the police.’

Metro visited the headquarters of Brent Police in north London to see the procedure in action.

The teenagers on the Kilburn estate may not believe it, but Brent is one of the best London boroughs when it comes to stop and search – in two years, the rate of arrests or ‘cannabis warnings’ being issued as a result from searches has increased from 16 per cent to 30 per cent, while crime is still falling.

There is a focus on intelligence-led policing and establishing correct grounds for searches. Statistics for each officer are carefully monitored and those whose ‘positive outcome rate’ is below par are sent for retraining.

In response to the claims of harassment, Detective Superintendent Simon Rose called on those aware of any abuses to complain.

He said: ‘I can obtain corroboration of any complaint from the GPS on the officer’s radio. If we have anonymous complaints, we can use undercover officers or actors posing as members of the public, create a fictitious call and see if the officers who are sent to the incident behave in the way claimed. If they do, we can prosecute or sack them.’

Police clearly have their work cut out. At the same time as trying to address the disproportionate figures of ethnic minorities being stopped, they are on the receiving end of political and public pressure to seize more weapons and drugs.

And some campaigners, such as actress Linda Robson, whose son was with 16-year-old Ben Kinsella in Islington when he was stabbed to death in 2008, have called for more stops to have a hope of tackling knife crime.

Police also face criminals who are well versed in dropping weapons under cars in anticipation of a search, or popping them down their underpants. Some offenders scoff when stopped by police who detect the smell of cannabis, gloating: ‘It’s too late, I’ve smoked it all.’

Technology may play a crucial part in reforming the system. With a camera in every pocket, officers who don’t behave professionally can end up on YouTube.

There is also an app set up by campaigners – and backed by police – which allows you to find out your rights and provide feedback on how you were treated.

In Greater Manchester, all stops are now processed via radio and no forms are filled out, so time and location are recorded automatically – bringing the average time for a stop and search down from 25 minutes to just three.

Labour’s Diane Abbott, MP for Hackney, has been campaigning on the issue for more than 25 years and said she fears the new consultation is just ‘window dressing’.

She told activists in Brent: ‘What you really want to focus in on is the professionalism, the accountability and the sense the police are able to give people that they are serving them rather than being an army of occupation.

‘What is it all for? Maybe what it’s for is not so much to find more knives but for the police to impose themselves on the community, to say “who run tings”.’

Ms Abbott told Metro: ‘The amount of crime picked up by stop and search is so small, relatively speaking, it’s hard to escape the conclusion that the level of stop and search among black and Muslim communities is driven by some assumptions about young people on the street.’

Does she mean racist assumptions?

‘I’m saying assumptions. People must judge for themselves what those assumptions are.’